Goessling explained to the assembled patients, family members and hospital staff that Thumbelina, who is 17.5 inches tall at the shoulders, is so small because she is a dwarf miniature horse, or, as he put it, a "mini-mini." According to the Guinness Book of World Records, Thumbelina isn't just the world's smallest living horse -- she's the smallest horse on record. Ever.

Thumbelina was born at Goose Creek Farms near St. Louis, where Goessling's parents breed miniature horses, which usually weigh 175 to 225 pounds as adults. She weighed just 8 pounds and wasn't expected to survive. Now 6 years old, she has avoided most of the major health problems that commonly afflict dwarf horses. Her legs are slightly crooked, but they serve her perfectly well thanks to a set of orthopedic horseshoes.

Ever since Thumbelina was a foal, the Goesslings noticed that she gravitated toward sick children.

"She has a way of seeking out kids who are suffering in some way," Goessling said.

And it's not surprising that she has a tendency to cheer them up. So, earlier this year, the Goesslings decided to take their show on the road and launched a national tour. When it ends in November, Thumbelina will have visited sick children in all 48 continental states. She also has spearheaded fundraising along the way -- since the tour began in April, Goessling estimates that Thumbelina has raised more than $100,000 for a variety of children's charities.

Thumbelina's presence was certainly appreciated at Arnold Palmer. The patients, many in wheelchairs, pulling their IVs behind them, were enthralled with Thumbelina and were eager to scratch her behind the ears, throw their arms around her neck and, in a couple of cases, give her a kiss on the nose.

"It's just really nice being able to get out, to not be locked in the hospital, and to get to see an animal," said Luis Adan, who is preparing for spinal-fusion surgery at Arnold Palmer.

Goessling fielded questions about Thumbelina's likes (her dog friend Cassie, baby horses, apples) and dislikes (baths, being poked in the eye by overzealous little fingers). Apparently, she is quite bossy and, as an infant, evicted Cassie from the doghouse because she decided she would like to live there herself.

Because Thumbelina's size is the byproduct of a rare genetic fluke, Goessling isn't too worried about another horse taking her title -- unlike Lake County's Dancer the dog, who briefly claimed the honor of being the world's smallest dog before Ducky from Massachusetts usurped him by a tenth of an inch.

But even if a tinier horse came along, Goessling said it wouldn't matter.

"We love Thumbelina whether she is or isn't the world's smallest horse," he said.

Helen Eckinger can be reached at 407-418-5981 or heckinger@orlandosentinel.com.